AB0928 USE OF RITUXIMAB IN SYSTEMIC SCLEROSIS PATIENTS WITH PULMONARY AND DIFFUSE CUTANEOUS INVOLVEMENT. A SERIES OF 15 CASES
Authors: F. Ortiz Sanjuan, E. Grau García, C. Riesco Barcena, H. Charia, A. V. Huaylla Quispe, I. Martínez Cordellat, L. Mas Sanchez, P. Muñoz Martinez, C. Nájera Herranz, R. Negueroles Albuixech, J. E. Oller Rodríguez, D. Ramos Castro, A. M. Torrat Noves, E. Tovar-Sugrañes, E. Vicens Bernabeu, I. Cánovas Olmos, S. Leal Rodriguez, L. Gonzalez Puig, J. Ivorra Cortés, J. A. Román Ivorra
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Systemic sclerosis (SSc) is often difficult to treat and the evidence in support of many of the usual therapies is limited. Abnormalities in B-cell function in SSc are thought to play a role in disease pathology. Furthermore, B-cell infiltrates have been demonstrated in both the skin and lung specimens in SSc. Rituximab (RTX) is a chimeric monoclonal antibody inhibiting CD20-mediated B-cell proliferation and differentiation that has shown promising results for pulmonary and cutaneous involvement of SSc. <h3>Objectives</h3> Our aim was to assess RTX for pulmonary and diffuse cutaneous involvement in real-life patients diagnosed of SSc. <h3>Methods</h3> Retrospective observational study of a wide and unselected series of patients diagnosed as SSc from a single university hospital from 2011 to 2022. Patients were classified as SSc following 2013 ACR/EULAR classification criteria. We reviewed pulmonary function through conventional spirometry and diffusing capacity of lung for carbon monoxide (DLCO). Pulmonary involvement was also assessed by high-resolution chest-CT test. Cutaneous involvement was assessed by modified Rodnan skin score (MRSS). <h3>Results</h3> We included 15 patients with a median [range] age (at the onset of RTX) of 53 [41-78] years (80% women; 20% men). The median [range] of time since diagnosis and treatment onset was 3 [0-12] years. At the diagnosis of SSc, no one of our patients evidenced a restrictive ventilatory pattern. DLCO was below normal limits in 12 patients (80%). Small airway obstruction expressed according decreased maximal (mid-) expiratory flow (MMEF) 25-75 was present in 1 patient (6.7%). Regarding cutaneous involvement, median MRSS at diagnosis was 18.3 [range 4-26]. RTX intravenous treatment regimen employed was 1000 mg (Day 1, followed by 1000 mg on day 15), with a repeat cycle every 6 months if required. After a median [range] follow-up period of 31 [6-100] months, 12 (80%) patients completed a total of 4 RTX cycles. An analysis of the pulmonary function showed that, after RTX, DLCO decreased in 2 of 15 patients (13.3%) and none presented worsening of MMEF 25-75. In all patients there was an improvement of cutaneous involvement. After a median follow-up of 31 [6-100] months during RTX therapy none of the patients presented any new relapse of cutaneous involvement or MRSS progression. The mean difference between MRSS measurement before and after RTX was 6.4±1.2. Only 2 of the patients (13.3%) had to discontinue RTX in the first term due to infusion-related reaction. After RTX treatment, 4 patients (26.7%) died (prostate cancer, SARS-COV-2 pneumonia, sudden cardiac arrest and ictus) has been well tolerated and no severe infections were reported. <h3>Conclusion</h3> In our experience, RTX seems to be a great option in real-life for those patients with pulmonary and diffuse cutaneous involvement due to SSc. However, cardiovascular, infectious and neoplastic complications should be assessed. <h3>References</h3> [1]Thoreau B, Chaigne B, Mouthon L. Role of B-Cell in the Pathogenesis of Systemic Sclerosis. Front Immunol. 2022;13:933468. [2]Morgan K, Woollard C, Beinart D, Host LV, Roddy J. Rituximab treatment for systemic sclerosis-associated interstitial lung disease: a case series of 13 patients. Intern Med J. 2022 Jun 7.Online ahead of print. [3]Narita Y, Funatogawa T, Mii K, Adachi H, et al. Use of Biologics for Systemic Sclerosis and Systemic Sclerosis-Associated Interstitial Lung Disease: Information from a Japanese Hospital Claims Database. Mod Rheumatol. 2022 Jun 2:roac055. Online ahead of print. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.